Types of Antibiotic-Resistant Infections

At NYU Langone, our doctors are experts in identifying the many types of antibiotic-resistant pathogens. 

Since the 1940s, antibiotics have been used to treat people with infectious diseases caused by bacteria. These medications greatly reduce illness and death from conditions such as tuberculosis and pneumonia. However, certain antibiotics have been used so widely and for so long that some bacteria that cause disease have become resistant to them, making these treatments less effective.

Antibiotic resistance occurs when the medication loses its ability to kill bacteria. As a result, the organisms continue to grow and cause infection, even in the presence of the antibiotic. 

Some bacteria are naturally resistant to certain types of antibiotics, but most become resistant through a natural genetic mutation or by acquiring resistance genes from other bacteria. When bacteria mate, they transfer their resistance traits.

Because bacteria can acquire many resistance traits over time, they can become resistant to different types of antibiotics. 

There are several common antibiotic-resistant pathogens.

Methicillin-Resistant Staphylococcus Aureus

Staphylococcus aureus is a pathogen commonly found on the skin or in the nose of healthy people. Most of the time, these bacteria are harmless, but they can cause an infection when they enter a wound. This type of bacteria is resistant to many antibiotics, including methicillin. 

Most methicillin-resistant Staphylococcus aureus, or MRSA, infections contracted outside of a hospital are skin infections. In medical centers, MRSA causes life-threatening bloodstream and surgical-site infections, as well as pneumonia. MRSA is one of the most common antibiotic-resistant bacteria.

Symptoms of MRSA infection often begin as small red bumps on the skin that can progress to deep, painful abscesses or boils, which are pus-filled masses under the skin. These need to be surgically opened and drained.

Sometimes MRSA stays on the skin, but it can invade the body, causing potentially life-threatening infections in bones, joints, the heart, and the lungs.

Streptococcus Pneumoniae 

Streptococcus pneumoniae bacteria cause many types of illnesses, including pneumonia, a lung infection. These bacteria can also lead to ear and sinus infections, as well as meningitis, an infection of the membranes around the brain and spinal cord. Bacteremia, a bloodstream infection, can also be caused by Streptococcus pneumoniae. 

This type of bacteria is spread through coughing, sneezing, and close contact with an infected person.

Symptoms depend on the part of the body infected. They can include fever, cough, shortness of breath, chest pain, stiff neck, confusion and disorientation, sensitivity to light, joint and ear pain, chills, sleeplessness, and irritability. Streptococcus pneumoniae can cause hearing loss, brain damage, and death if the infection is severe.

Carbapenem-Resistant Enterobacteriaceae

Enterobacteriaceae are a family of bacteria that include pathogens found in the digestive tract as well as the environment, including Escherichia coli (E. coli), Salmonella, and Shigella, among others 

The bacteria can live in the intestines without causing disease. But if food or water is contaminated by certain strains of Enterobacteriaceae, they can cause food poisoning or gastroenteritis, the main symptoms of which are vomiting and diarrhea.

These organisms sometimes spread outside the gut and cause serious infections of the urinary tract, bloodstream, or wounds. Most of these infections occur in hospitals and other healthcare settings and are associated with catheters and surgical procedures. 

Carbapenem is an antibiotic used to treat some antibiotic-resistant infections caused by Enterobacteriaceae. However, the bacteria can also become resistant to carbapenem. If this occurs, the bacteria are called carbapenem-resistant Enterobacteriaceae.